Ligand-gated and voltage-regulated ion channels on the surface of excitable cells mediate synaptic transmission and neurosecretion. Not surprisingly, mutations of ion channel genes contribute to a wide variety of pathological disorders that can affect neural differentiation and cause neurodegeneration. This proposal is multi-disciplinary ranging from molecular structure, regulation of ion channel function using biophysical techniques, cell biology, to studying the effects of ion channel mutations on animal behavior. The channels being studied include the multimeric gated nicotinic acetylcholine and glutamate receptors and the voltage-gated calcium channels. These ion channels provide important sites for pharmacological intervention in disease status, such as, addiction, epilepsy, and neuronal death due to trauma or stroke, as well as neurodegenerative disease. Approaches being exploited include, expression and analysis of protein domains by NMR, reconstitution of normal or genetically modified ion channels in cell lines to determine their binding and interaction with neurotoxins, patch-clamp analysis to examine the biophysical properties of channel splice variants, modulation ion channels by scaffolding proteins and protein phosphorylation, slice-recording and analysis of animal behavior. Within this context we will use transgenic methods for targeted ion channel knock-out and knock-in experiments to further reveal the physiological consequences of specific channel mutations and to elucidate the physiological roles of specific channel subunits combinations.